A wide variety of technologies are utilized to remediate contaminated groundwater, including the method of pumping groundwater to the surface and treating groundwater in reactors, or bioremediation with microbial populations in situ, or ex situ, or injection of catalysts into the ground to encourage natural remediation of contaminants in groundwater.
In Horn, U.S. Pat. No. 5,635,394, a bioreactor is disclosed which serves as a biological air filter for purification of air streams. In Fernandao, et al., U.S. Pat. No. 5,616,253 and U.S. Pat. No. 5,611,936, various methods are disclosed for utilizing a palladized iron bimetallic system for the dechlorination of chlorinated organic compounds in contaminated soils and various effluents. In Howson, et al., U.S. Pat. No. 5,543,059, a method is disclosed for remediation of contaminated solutions by a tiered metal wall or column having reducing metal particles, to dehalogenate hydrocarbon contaminants. In Sivavec, U.S. Pat. No. 5,447,639, a method is disclosed for remediation of aqueous solutions of chlorinated aliphatic hydrocarbons utilizing in situ or ex situ reactions with ferrous sulfide. In Thornton, U.S. Pat. No. 5,380,441, a method is disclosed for the addition of metallic iron particles to an aqueous solution containing hexavalent chromium to precipitate and reduce the hexavalent chromium to trivalent chromium. In Gillham, U.S. Pat. No. 5,266,213, a method is disclosed for remediation of aqueous halogenated organic compounds utilizing a metal in a trench to produce reducing conditions.
The above described and other methods of remediation have shortcomings which require the installation of an in situ permanent or semi-permanent reactor apparatus to contact contaminated groundwater. A commonly used method of remediation requires that groundwater is pumped to the surface into reactors containing reacting agents for treatment. Continuous pumping of groundwater is costly and inefficient, and in situ placement of remediation mechanisms can be obstructed underground by clogging and biological fouling of filters. Thus there exists room for improvement within the art.